A new bridge across the Thames linking two Surrey towns is the first new vehicle crossing over the river for 20 years. NCE reports.
The first new vehicle crossing point to be built across the Thames for 20 years is taking shape as a Costain team spans the river between Walton-on-Thames and Shepperton.
The area has been served for many years by two bridges that were intended to be temporary links. A road bridge was built in the 1950s as a replacement for a war-damaged structure. It now caters purely for pedestrians and cyclists, while another temporary bridge that opened in 1999 carries road traffic.
The contract for the new bridge was originally awarded by Surrey County Council in 2005 but the project has been the subject of two public inquiries and was put on hold during a government spending review. Costain started detailed design for the final time in 2011, with some advance works getting underway the same year and actual construction starting in January 2012.
The bridge’s design is known as a thrust arch - similar to the more familiar bowstring arch. The striking arches have recently been put in place. When complete, the bridge will have a clear span of 90m, but this figure rises to 148m when taking into account the entire structure and links in to existing roads.
Technical challenges, says Costain project manager Andy Bannister, include poor ground conditions on the Walton-on-Thames side of the river. Costain will build a separate viaduct over a flood plain to link up with the bridge itself.
Other factors to be negotiated include the presence of the Thames Pathway, which goes through the job site. “There’s a huge public and business interface,” says Bannister.
The bridge is due to be handed over in summer 2013. The old bridges will then be demolished, with final tie-in works and landscaping to be completed in spring 2014.